Teratogenic effects of gravitational changes.

In investigating the effect of gravitational changes on development, it is instructive to think of altered gravity (delta g) as a teratogen--that is, an environmental factor influencing development. Observed effects on skeletal development include: suppression of morphogenesis in centrifuged mouse limb buds; advanced fusion stages in centrifuged mouse palates; smaller crown rump lengths (CRL) and decreased number of pregnancies in centrifuged rats and mice; altered differentiation of growth plates in young growing rats in space; and decreased length of calcified long bone regions in fetal rats exposed to microgravity in utero. These studies show that delta g is able to alter development in vivo and in vitro and suggest that delta g operates, at least in part, at the cellular level.     

Decision fusion analysis detects spiral bevel gear damage

A diagnostic tool for detecting damage to spiral bevel gears was developed. Two different monitoring technologies - oil debris analysis and vibration were integrated using data fusion into a health monitoring system for detecting surface fatigue pitting damage on gears. This integrated system showed improved detection and decision-making capabilities as compared to using individual monitoring technologies. This diagnostic tool was evaluated by collecting vibration and oil debris data from fatigue tests performed in the NASA Glenn Spiral Bevel Gear Fatigue Rigs. Data was collected during experiments performed in this test rig when pitting damage occurred. Results show that combining the vibration and oil debris measurement technologies improves the detection of pitting damage on spiral bevel gears.     

Capability of Bhaskara-II satellite microwave radiometer brightness temperature data to discriminate soil moisture conditions of Indian landmass

With the objective of developing Microwave Remote Sensing technology in the country, India has launched a series of Satellites Bhaskara-I and II with the microwave radiometer capability. In this paper, an attempt is made to demonstrate the capability of the brightness temperature data acquired by these radiometers to discriminate various soil moisture conditions of Indian land mass. The analysis show that large areas assessment of soil moisture is possible to a limited extent.     

The resonance cone technique for exciting electron acoustic waves in equatorial ionosphere

A rocketborne R.F. resonance cone technique is discussed in this paper. The technique is ideal over the geomagnetic equator where the earth's magnetic field is horizontal. The R.F. exciter is fixed along the axis of the rocket. By measuring the semi-angle of this cone various plasma parameters can be derived, such as electron density and temperature.     

Mass loading of planetary atmospheres by rocky satellites—II: Transport and enhanced lifetimes of satellite ejecta in planetary magnetospheres

Extensive studies have been conducted concerning individual mass, temporal and positional distribution of submicron rocky ejecta existing in the satellite-planetary gravitational sphere of influence. The transit time of the major portion of the ejecta that is transported from the satellite's gravitational sphere of influence to the planetary magnetopause is about one week and represents a mass loading pulse occurring each satellite orbit. The mass-flux distributions of lunar ejecta at the surface of the magnetopause for a complete lunar orbit are presented. Spatial mass densities of lunar ejecta in specific zones of the magnetosphere provide a means to compare sporadic interplanetary dust spatial mass densities in the same zones.     

Trace constituents measurements deduced from spectrometric observations on-board spacelab

The observation of infrared absorption lines by means of a grille spectrometer on board Spacelab 1 allows the determination of Co₂ and CO in the low thermosphere and in the middle atmosphere. Equal abundances of CO and CO₂ are found at 115 ± 5 km altitude. CO₂ is observed to depart from its homospheric volume mixing ratio near 100 km, dropping by a factor of 10,15 km higher. The CO largest number density is observed near 70 km altitude, close to the H Lyman alpha photoproduction peak.The analysis of one run dedicated to the observation of water vapor shows a middle atmospheric mixing ratio of this species within the limits : 3 to 8 ppmv up to 70 km altitude, with the indication of an increase from 30 to 50 km altitude. The H₂O mixing ratio drops very rapidly above 70 km.The comparison of the results from strong and weak H₂O and CO₂ lines shows the need to refine the line profile model.     

Differential GPS dynamic location experiments at sea

Differential GPS on board naval vessels has been tested in severe multipath archipelago environment against a commercial laser tracker system. The average location difference was 3 meters and two periodic error components were found. Their tune constants were 1.8 and 28 seconds and the peak amplitudes 1.5 and 1.1 meters, respectively. In addition to these, a clear dependency of location error standard deviation figures on the GPS antenna mounting distance from the sea level was observed.     

Anti-aircraft artillery simulator

Air defense systems protect land and maritime resources from air attack. Depending on the regional characteristics and type of conflicting forces, air defense threats vary considerably. In regional conflicts, where forces with similar capabilities are involved and no air-superiority can be achieved, the role of air defense systems becomes critical. In combat terrains containing mountains (in mainland or in small islands), the man-operated or computer-controlled (using passive sensors) anti-aircraft artillery can be highly effective. The simulator presented in this work aims to exploit the capabilities provided by current commercial-off-the-shelf (COTS) communication and multimedia technologies for providing a training environment that improves the personnel capability for effective use of man-controlled anti-aircraft weapons.     

Proposed optical observations of Comet Halley

A comprehensive programme is proposed for optical observations of Comet Halley based on the wide range of available facilities such as photometers, monochromators, interferometers and a polarimeter. Feasibility study of the proposed investigations with reference to existing facilities is carried out for each technique and needs for additional instrumentation are established. Conclusions for optimum utilization of existing facilities are presented.